CVE-2021-39924

Large loop in the Bluetooth DHT dissector in Wireshark 3.4.0 to 3.4.9 and 3.2.0 to 3.2.17 allows...

7.5 HighFix available

Large loop in the Bluetooth DHT dissector in Wireshark 3.4.0 to 3.4.9 and 3.2.0 to 3.2.17 allows denial of service via packet injection or crafted capture file

Attack profile

How easy it is to exploit

Attack vector: Network
Complexity: Low
Privileges needed: None
User interaction: None

What an attacker can affect

Confidentiality: None
Integrity: None
Availability: High

Exploit likelihood

5.29%Up 4.3 points since Nov 20, 2021

What each source reports

CVE List Score used 7.5

Large loop in the Bluetooth DHT dissector in Wireshark 3.4.0 to 3.4.9 and 3.2.0 to 3.2.17 allows denial of service via packet injection or crafted capture file

Record: CVE-2021-39924
CVSS 3.1: 7.5 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Updated: 2026-11-02

EUVDEUVD-2021-26280 7.5

Large loop in the Bluetooth DHT dissector in Wireshark 3.4.0 to 3.4.9 and 3.2.0 to 3.2.17 allows denial of service via packet injection or crafted capture file

Record: EUVD-2021-26280
CVSS 3.1: 7.5 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Updated: 2026-11-03

GitHub AdvisoriesGHSA-7qp4-qv4w-q6jm 7.5

Large loop in the Bluetooth DHT dissector in Wireshark 3.4.0 to 3.4.9 and 3.2.0 to 3.2.17 allows...

Large loop in the Bluetooth DHT dissector in Wireshark 3.4.0 to 3.4.9 and 3.2.0 to 3.2.17 allows denial of service via packet injection or crafted capture file

Record: GHSA-7qp4-qv4w-q6jm
CVSS 3.1: 7.5 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Weakness: CWE-834
Updated: 2026-11-02

NVD 7.5

Large loop in the Bluetooth DHT dissector in Wireshark 3.4.0 to 3.4.9 and 3.2.0 to 3.2.17 allows denial of service via packet injection or crafted capture file

Record: CVE-2021-39924
CVSS 3.1: 7.5 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CVSS 2.0: 5.0 MediumAV:N/AC:L/Au:N/C:N/I:N/A:P
Weakness: CWE-834
Updated: 2026-11-02

OSVALPINE-CVE-2021-39924 7.5

Large loop in the Bluetooth DHT dissector in Wireshark 3.4.0 to 3.4.9 and 3.2.0 to 3.2.17 allows denial of service via packet injection or crafted capture file

Record: ALPINE-CVE-2021-39924
CVSS 3.1: 7.5 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Updated: 2026-11-03

OSVAZL-7412 7.5

CVE-2021-39924 affecting package wireshark for versions less than 3.4.14-1

Large loop in the Bluetooth DHT dissector in Wireshark 3.4.0 to 3.4.9 and 3.2.0 to 3.2.17 allows denial of service via packet injection or crafted capture file

Record: AZL-7412
CVSS 3.1: 7.5 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Updated: 2026-11-02

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OSV 7.5

Large loop in the Bluetooth DHT dissector in Wireshark 3.4.0 to 3.4.9 and 3.2.0 to 3.2.17 allows denial of service via packet injection or crafted capture file

Record: CVE-2021-39924
CVSS 3.1: 7.5 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Updated: 2026-11-02

OSVDEBIAN-CVE-2021-39924 7.5

Large loop in the Bluetooth DHT dissector in Wireshark 3.4.0 to 3.4.9 and 3.2.0 to 3.2.17 allows denial of service via packet injection or crafted capture file

Record: DEBIAN-CVE-2021-39924
CVSS 3.1: 7.5 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Updated: 2026-11-02

OSVUBUNTU-CVE-2021-39924 7.5

Large loop in the Bluetooth DHT dissector in Wireshark 3.4.0 to 3.4.9 and 3.2.0 to 3.2.17 allows denial of service via packet injection or crafted capture file

Record: UBUNTU-CVE-2021-39924
CVSS 3.1: 7.5 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Updated: 2026-11-02

OSVMGASA-2021-0518 No score

Updated wireshark packages fix security vulnerability

IPPUSB dissector crash (CVE-2021-39920). Modbus dissector crash (CVE-2021-39921). C12.22 dissector crash (CVE-2021-39922). PNRP dissector large loop (wnpa-sec-2021-11). Bluetooth DHT dissector large loop (CVE-2021-39924). Bluetooth SDP dissector crash (CVE-2021-39925). Bluetooth HCI_ISO dissector crash (CVE-2021-39926). IEEE 802.11 dissector crash (CVE-2021-39928). Bluetooth DHT dissector crash (CVE-2021-39929).

Record: MGASA-2021-0518
Updated: 2026-11-02

OSVopenSUSE-SU-2021:1566-1 No score

Security update for wireshark

This update for wireshark fixes the following issues:

Update to Wireshark 3.4.10:
CVE-2021-39920: IPPUSB dissector crash (bsc#1192830).
CVE-2021-39921: Modbus dissector crash (bsc#1192830).
CVE-2021-39922: C12.22 dissector crash (bsc#1192830).
CVE-2021-39924: Bluetooth DHT dissector large loop (bsc#1192830).
CVE-2021-39925: Bluetooth SDP dissector crash (bsc#1192830).
CVE-2021-39926: Bluetooth HCI_ISO dissector crash (bsc#1192830).
CVE-2021-39928: IEEE 802.11 dissector crash (bsc#1192830).
CVE-2021-39929: Bluetooth DHT dissector crash (bsc#1192830).

This update was imported from the SUSE:SLE-15:Update update project.

Record: openSUSE-SU-2021:1566-1
Updated: 2026-11-02

OSVopenSUSE-SU-2021:3938-1 No score

Security update for wireshark

This update for wireshark fixes the following issues:

Update to Wireshark 3.4.10:
CVE-2021-39920: IPPUSB dissector crash (bsc#1192830).
CVE-2021-39921: Modbus dissector crash (bsc#1192830).
CVE-2021-39922: C12.22 dissector crash (bsc#1192830).
CVE-2021-39924: Bluetooth DHT dissector large loop (bsc#1192830).
CVE-2021-39925: Bluetooth SDP dissector crash (bsc#1192830).
CVE-2021-39926: Bluetooth HCI_ISO dissector crash (bsc#1192830).
CVE-2021-39928: IEEE 802.11 dissector crash (bsc#1192830).
CVE-2021-39929: Bluetooth DHT dissector crash (bsc#1192830).

Record: openSUSE-SU-2021:3938-1
Updated: 2026-11-02

OSVopenSUSE-SU-2024:11641-1 No score

libwireshark14-3.4.10-1.1 on GA media

These are all security issues fixed in the libwireshark14-3.4.10-1.1 package on the GA media of openSUSE Tumbleweed.

Record: openSUSE-SU-2024:11641-1
Updated: 2026-11-02

OSVSUSE-SU-2021:3938-1 No score

Security update for wireshark

This update for wireshark fixes the following issues:

Update to Wireshark 3.4.10:
CVE-2021-39920: IPPUSB dissector crash (bsc#1192830).
CVE-2021-39921: Modbus dissector crash (bsc#1192830).
CVE-2021-39922: C12.22 dissector crash (bsc#1192830).
CVE-2021-39924: Bluetooth DHT dissector large loop (bsc#1192830).
CVE-2021-39925: Bluetooth SDP dissector crash (bsc#1192830).
CVE-2021-39926: Bluetooth HCI_ISO dissector crash (bsc#1192830).
CVE-2021-39928: IEEE 802.11 dissector crash (bsc#1192830).
CVE-2021-39929: Bluetooth DHT dissector crash (bsc#1192830).

Record: SUSE-SU-2021:3938-1
Updated: 2026-11-02

Affected products

Affected packages

Affected packages
Package	Affected	Fixed
`wireshark` Alpine:v3.15	3.2.0 up to 3.4.13-r0	3.4.13-r0
`wireshark` Alpine:v3.16	3.2.0 up to 3.4.11-r0	3.4.11-r0
`wireshark` Alpine:v3.17	3.2.0 up to 3.4.11-r0	3.4.11-r0
`wireshark` Alpine:v3.18	3.2.0 up to 3.4.11-r0	3.4.11-r0
`wireshark` Alpine:v3.19	3.2.0 up to 3.4.11-r0	3.4.11-r0
`wireshark` Alpine:v3.20	3.2.0 up to 3.4.11-r0	3.4.11-r0
`wireshark` Alpine:v3.21	3.2.0 up to 3.4.11-r0	3.4.11-r0
`wireshark` Alpine:v3.22	3.2.0 up to 3.4.11-r0	3.4.11-r0
`wireshark` Alpine:v3.23	3.2.0 up to 3.4.11-r0	3.4.11-r0
`wireshark` Alpine:v3.24	3.2.0 up to 3.4.11-r0	3.4.11-r0

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Affected packages
Package	Affected	Fixed
`wireshark` Azure Linux:2	before 3.4.14-1	3.4.14-1
`wireshark` Debian:12	before 3.6.0-1	3.6.0-1
`wireshark` Debian:13	before 3.6.0-1	3.6.0-1
`wireshark` Debian:14	before 3.6.0-1	3.6.0-1
`wireshark` Debian:9 From an advisory covering 9 CVEs	before 2.6.20-0+deb9u2, plus listed versions 2.2.6+g32dac6a-22.2.6+g32dac6a-2+deb9u12.2.6+g32dac6a-2+deb9u22.2.6+g32dac6a-2+deb9u32.2.7-1 Show 25 moreShow less 2.4.0-12.4.1-12.4.2-12.4.3-12.4.4-12.4.5-12.4.6-12.6.1-12.6.10-12.6.2-12.6.2-22.6.20-0+deb9u12.6.3-12.6.3-1~deb9u12.6.4-12.6.4-22.6.5-12.6.5-1~deb9u12.6.6-12.6.7-12.6.7-1~deb9u12.6.8-12.6.8-1.12.6.8-1.1~deb9u12.6.9-1	2.6.20-0+deb9u2
`wireshark` Debian:11 From an advisory covering 12 CVEs	before 3.4.10-0+deb11u1, plus listed versions 3.4.4-13.4.6-1~exp13.4.7-13.4.7-1~exp13.4.8-13.4.9-1	3.4.10-0+deb11u1
`wireshark` Mageia:8 From an advisory covering 8 CVEs	before 3.4.10-1.mga8	3.4.10-1.mga8
`wireshark` SUSE:Linux Enterprise Module for Basesystem 15 SP2 From an advisory covering 8 CVEs	before 3.4.10-3.62.1	3.4.10-3.62.1
`wireshark` SUSE:Linux Enterprise Module for Basesystem 15 SP3 From an advisory covering 8 CVEs	before 3.4.10-3.62.1	3.4.10-3.62.1
`wireshark` SUSE:Linux Enterprise Module for Desktop Applications 15 SP2 From an advisory covering 8 CVEs	before 3.4.10-3.62.1	3.4.10-3.62.1
`wireshark` SUSE:Linux Enterprise Module for Desktop Applications 15 SP3 From an advisory covering 8 CVEs	before 3.4.10-3.62.1	3.4.10-3.62.1
`wireshark` Ubuntu:Pro:14.04:LTS	All versions, plus listed versions 1.10.2-11.10.3-11.10.5-1ubuntu11.10.5-21.10.6-1 Show 9 moreShow less 1.12.1+g01b65bf-4+deb8u11ubuntu0.14.04.12.6.3-1~ubuntu14.04.12.6.4-2~ubuntu14.04.12.6.5-1~ubuntu14.04.12.6.6-1~ubuntu14.04.02.6.8-1~ubuntu14.04.0~esm12.6.10-1~ubuntu14.04.0~esm12.6.10-1~ubuntu14.04.0~esm22.6.10-1~ubuntu14.04.0~esm3	None known
`wireshark` Ubuntu:Pro:16.04:LTS	All versions, plus listed versions 1.12.7+g7fc8978-11.12.8+g5b6e543-22.0.1+g59ea380-3build12.0.2+ga16e22e-12.2.6+g32dac6a-2ubuntu0.16.04 Show 8 moreShow less 2.6.3-1~ubuntu16.04.12.6.4-2~ubuntu16.04.02.6.5-1~ubuntu16.04.02.6.6-1~ubuntu16.04.02.6.8-1~ubuntu16.04.02.6.10-1~ubuntu16.04.02.6.10-1~ubuntu16.04.0+esm12.6.10-1~ubuntu16.04.0+esm2	None known
`wireshark` Ubuntu:Pro:18.04:LTS	All versions, plus listed versions 2.4.2-12.4.3-12.4.4-12.4.5-12.6.3-1~ubuntu18.04.1 Show 7 moreShow less 2.6.4-2~ubuntu18.04.02.6.5-1~ubuntu18.04.02.6.6-1~ubuntu18.04.02.6.8-1~ubuntu18.04.02.6.10-1~ubuntu18.04.02.6.10-1~ubuntu18.04.0+esm12.6.10-1~ubuntu18.04.0+esm2	None known
`wireshark` Ubuntu:Pro:20.04:LTS	All versions, plus listed versions 3.0.5-13.0.7-13.2.1-13.2.2-13.2.3-13.2.3-1ubuntu0.1~esm13.2.3-1ubuntu0.1~esm2	None known
`wireshark` Ubuntu:Pro:22.04:LTS	All versions, plus listed versions 3.4.7-1~exp13.4.9-13.6.2-1ubuntu13.6.2-23.6.2-2ubuntu0.1~esm1	None known
`wireshark` Ubuntu:24.04:LTS	All versions, plus listed versions 4.0.8-14.0.10-14.0.11-14.2.0-14.2.2-14.2.2-1.1build14.2.2-1.1build24.2.2-1.1build3	None known
`wireshark` Ubuntu:25.10	All versions, plus listed versions 4.4.5-14.4.6-24.4.6-2build14.4.7-1	None known
`wireshark` Ubuntu:26.10	All versions, plus listed versions 4.6.4-14.6.6-14.6.6-24.6.6-2build1	None known
`wireshark` Ubuntu:26.04:LTS	All versions, plus listed versions 4.4.7-14.6.0-14.6.1-24.6.2-34.6.3-14.6.4-1	None known
`wireshark` openSUSE:Leap 15.2 From an advisory covering 8 CVEs	before 3.4.10-lp152.2.21.1	3.4.10-lp152.2.21.1
`wireshark` openSUSE:Leap 15.3 From an advisory covering 8 CVEs	before 3.4.10-3.62.1	3.4.10-3.62.1
`wireshark` openSUSE:Tumbleweed From an advisory covering 8 CVEs	before 3.4.10-1.1	3.4.10-1.1

History

History
Recorded	Changed	Sources
Nov 6, 2026	affected, facts
Nov 3, 2026	affected, aliases, references	OSV
Nov 3, 2026	aliases	EUVD
Nov 2, 2026	first indexed	CVE List, GitHub Advisories, NVD, OSV

Dates are when Every CVE recorded each change. Upstream dates may differ.

In short

CVE-2021-39924 is a high vulnerability (CVSS 7.5) in Wireshark, published November 19, 2021. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 5.29%, the 92nd percentile. Fixed in wireshark 3.4.13-r0.

References

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